Bringing back an older discussion, "Good Eats" on the Food Network
here in the states just had an episode addressing food myths.

Perhaps the most useful to me, personally, is the debunking of the
myth that mushrooms absorb a lot of water so you should brush them off
rather than washing them. While they do absorb some water, it really
is very little. So just rinse the 'shrooms off and don't waste time
brushing them.

Anyway, they also addressed the "water exploding in the microwave"
myth. All of the issues we had brought up here - superheating of the
water, nucleation sites, etc -- were mentioned. The "on air"
demonstration did, in fact, explode.

The point that was made, however, was that the water has to be kept
still. They used a Snapple-type bottle, which had a relatively small
opening compared with the volume of water. When it exploded, it
emptied about 2/3 of the water.

The suggestions were to always use a wide-mouth container, and to stir
it every couple of minutes. This prevents the stillness of the water
which is necessary for superheating.

So, in conclusion, we appear to have come to the correct conclusions.

--
Derek

"Judge of a man by his questions rather than by his answers." --
Voltaire